Simplified hobber



June 28 1927 w. F. ZIMMERMANN S IMPLIFIED HOBBEK Original Filed Aug. 27, 1924' 3 Sheets-Sheet l Smvewtoz wmZZa 9T @lbtomw June 1927' w. F. ZI'MMERMANN SiMPLIF'iED HOBBERI ori inal Filed A112. 27, 1924 s Sheets-Sheet June 28; 1927. v

w. F. ZIMMERMANN SIMPLIFIED HOBBER Original Filed Aug. 27, 1924 s Sheets-Sheet 3 Enowntoz Patented June 28, 1927.

UNITED STATES PATENT OFFIfiE.

VJILLIAM F. ZIMMERMANN, OF MAPLEVVOOD, NEW JERSEY, ASSIGNOR T0 GOULD Sz EBERHARDT, OF NEWARK, JERSEY, A CORPORATION OF NEW'J'ERSEY. I

SIMPLIFIED HOBBEB.

Original application filed August 27, 1924, Serial No. Z34,487. Divided and this application filed lanuary 17, 1925. Serial No. 3,021.

This invention relates to bobbing-ma chines;. this application being a division of a parent copending application No. 734,487, filed August 27, 1924.

In said parent application, there is dis closed a unique machine having a bodilyshiftable stanchion, a non-shiftable workcarrier and balanced drives terminating respectively in worm-wheels for rotating the cutter-spindleand the work-spindles respectively. ,That structural skeleton is characterizedby a notable simplicity; and it is to that subject-matter that this divisional application is devoted; the parent application being relied upon to cover more especially the various control-mechanisms whereby the machine may be, manually and automatically, so controlled as to realize most fully its inherent capacity for a high production of gears.

In devising thest-ructural arrangement herein disclosed, I have undertaken so to improve upon the mechanism of my prior U. S. Patent No. 1,472,?67 that the principles of construction thereof may be carried forward and utilized in an even more simple, rigid and sturdy manner, and at the same time render available a machine exhibiting various conveniences in point of an invariable location of the work to keep it uniformly within reach of the user, and at the same time to provide a superior way of supporting the cutter; all in efiective rela tion with a balanced few-part transmission system. i

By the term balanced drive as used herein is meant a special relationship between the elements connecting the driven cutter spindle and the driven work spindle respectively with the common source of power; said relationship being such that neither branch presents more sources of backlash, such as pairs of intermeshinggear-teeth, than the other branch; thereby reducing disproportions in vibrations and minimizing the tendency to chatter under the intermite tent releases of successive teeth from the work. c

To eliminate the intervention of a worksuppor-ting carriage between the bed and the worksupporting spindle is an ObJQC-tlVQ of this invention; this being accomplished by journaling that spindle directly in thebed of the machine nearone e d and s0 devisdesirable characteristics of an anvil so that the work is supported thereby in a manner well adapted to receive, Without manifesting vibration, the hammer-like blows of. the successively acting teeth of the hob; (3rd) the work spindle is always located at the same place with respect to the end of thebed and thus is at all times equally withinthe easy reach of the attendant whether for cutting gears of larger or of small diameters; and

(4th) the fixed position of the spindle on the'bed enables a larger worm-wheel to be afiixed to its spindle and enables the bed casting to be reinforced and made more rigid with the same weight of metal than it clearances for the travel of the enclosed wormwheel had to be provided.

To take advantage of the otherwise necessary massiveness of the stanchion by utiliz ing'it in a steadying capacity is likewise within the objective of this invention. The stanchion, which is virtually a part of the bed, has to be provided asa support for the hob and, as the hob is necessarily located some distance from the plane of the bed, the stanchion must be large and, being large, it must be heavy and massive so that it may not flex or quiver under the action of the hob. Now, by making this rather ponderous element capable of being slid on the bed (through an agency such as will be in dicated) it has the general characteristics of a shiftable anvil and is, by its very massiveness, capable of absorbing the shocks largely independently of any means for clamping it to the bed. Furthermore, its

great weight tends to hold it firmly on the ways of the bed and that weight acts in the same direction as the clamping elements and hence the stanchion admits of being better and more rigidly secured to the bed by the same clamping force as a relatively thin carriage which naturally tends to deflect and thus localize the clamping pressures. Also, being large, the stanchion provides a base of ample dimensions and those proportions are adequate for the needs of a slidable element and do not have to be enlarged; so that, by eliminating the carriage and thus reducing the number of major elements of the machine, a saving of the equivalent weight of metal may be accomplished and yet a more rigid construction attained. To slide the heavy stanchion, as will be perceived by reference to my parent application a power traverse mechanism may be employed to enable the user to perform that labor without effort; means for accomplishing that initial movement by manual power being also available as shown herein.

The aforesaid structural skeleton, with its attendant advantages, has been combined with a simplified system of driving elements organized in an arrangement harmonizing with said structural skeleton and presentn'ig the advantages of a balanced drive; all of which will become manifest by referring to the accompanying drawings, in which:

Fig. 1 is a side elevation of a hobbingmachine showing a fined work spindle and a shiftable stanchion supporting a hob-carrying head slidable thereon; all in combination with acompatible simplified balanced drive. Fig. 2 is a skeleton of the balanced-drive traiismission system for performing the various movements of the working and positioning elements of the machine. Figs. 3 and 4 are rear and front end-elevations, respectively, of the machine showing further details of the manner of combining the balanced drive with the major frame elements of the machine.

The bed A, in this embodiment, is elongated and positioned horiz ontally and provides a forward working region in which the work spindle is directly journaled as to occupy a fixed position, and the bed brovides also a rear ineehanism-supporting region on which the stanchion is slidably mounted. The work spindle lV sl'iown Journaled in fixed. bearings A and it err-- tends downwardly into the interior of the bed as indicated by W and, at its lower end, carries a worm-wheel W by which it i driven. The portion of the bed that hen, the worm-wheel N is apppropriately cm larged to contain that wheel and, it much as the wheel occupies a fixed position in space, the bed admits of being ribbed and reinforced closely to the wheel and thus made very rigid as will he understood without illustration. It is noteworthy that by thus giving the w rk spindle fixed position at the forward end of the bed, it is at times quickly accessible to the user and it is not at one time further from the end of the bed than at another as often happens when the work spindle is shiltablc in position. The mounting of the spindle is accomplished in a very solid manner with the object of realizing the effect of an anvil so that it virtually supports the work substantially as solidly as though it was clamped to the bed itself and, in consequence, the tendency to vibrate and chatter is reduced to a minimum.

The stanchion S is in the nature of a heavy box-like casting which is provided with slideways S and S at right angles to one another; the slideways S resting on the slideways S provided by the surface of the bed and arranged to permit the heavy stanchion to he slid towards and away from the axis of the work spindle for the purpose of determining the diameter of the gear G to be cutby the machine. The purpose of the transverse slidways S is to support and guide ahead H which is thus shiftable in parallelism with the axis of the work-spin die so that the cutter or hob (whicn is carried by the head) may in the course of the feeding movement cut the teeth of the gear G. It will be understood that. this head H is suitably gibbed to the slideways S and, in order to counterbalance the weight of the head H, a counterweight H may be arranged to rise and descend in an appropriate well provided by the stanchion S; conventional ropes'and pulleys P and H being provided as will be understood.

It is to be noted that the stanchion, being heavy and massive, is in effect a part of the solid bed itself because when clamped down to that bed, it becomes very solid therewith owing to. the action of the clamps augmented by the weight of the stanchion and by reason of the fact that the base of the. stanchion S is very extensive so as to resist effectively such overturning forces as result from the pressure the hob again..." the work during the tool' g operation. i will likewise be noted that, in cutting spur gears, the stanchion requires to be shifted only when a change is to he made in the di ameter of the spur gears being cut (which ordinarily would be quite infrequent) and it will. also be noted that the shifting of the stanchion does not reduce the facility of access of the user to the work spindle and does not interpos'e obstructions when brought closer to that spindle. It willalso be noted that the slideways S at tie base of the stanchion runs to a region substantially underlying the head H so that this construction avoids the objectionable overhang which is necessitated whenever the work-spindle is mounted on a carriage which slides on the. bed.

The simplified transmission system for rotating both the work spindle and the hob, and for progressively feeding the head H,

and for shifting the position of the stanchion S, and for varying the rates of rotations and for shifting the parts quickly or slowly as the case may be, will now be described. V

This transmission is in the nature of a balanced drive and comprehends an intermediate splined shaft X and. two main transmission shafts Y and Z: thehob-driving shaft Y. being also splined. These two shafts are disposed at right angles and the intermediate shaft is parallel with. one of them; the latter being in this embodiment the non-splined shaft that communicates motion to the work spindle. The intermediate shaft receives the power in the first instance; this being accomplished by the power-line consisting of a pulley P or other prime mover, the power shaft P and appropriate gears such, for example, as the two spur gears P and P and the two angle gears P and P The hob-drivingsplined transmission shaft Y is journaled in the shiftable stanchion so as bodily to travel therewith in'a direction parallel with the intermediate shaft and, at its lower end, it is provided with an angle gear y which meshes with a shiftable angle gear 00 which is splined to the intermediate shaft X. The cutter C is mounted on a spindle c which is journaled in the head H at an appropriate angle to compensate'for the helix-angle of the hob used for cutting the spur teeth. This angle may be in the neighborhood of live degrees for a single thread hob or ten degrees for a double thread hob. This angle being fixed and not of great magnitude admits of a very simple and direct driving connection between the spindle c and the splined trans mission shaft Y. That 1s to say, a. worm 1 is splined to the shaft Y and is jouriialed in the head H so that, as the head moves up or down, the worm will be corrospoiidingly shifted on the shaft Y and a worm-wheel c is affixed to the end of the spindle 0 and its teeth are so cut, with a skew-gear effect, that the meshing will be perfect although the worm and worm-wheel are at an angle to each other.

i The other non-splined transmission shaft Z is journaled in the bed of the machine and has a worm a aiiixed thereto for'driving the spindle WV through the worm-wheel W The single pair of change gears 00 and 2 establish the driving relation between the intermediate power shaft X and the trans-v mission shaft Z; it being observed that this arrangement provides a balanced drive in which the four gears'l i, a, e and m transinit the motion tothe work spindle, and

likewise four gears c, y, y and :11 transmit the motion to the cutter.

To start the machine,thepower lever B is actuated. This shifts the collar 8 and rotatable feed-screw F.

slides a long key 9 (which is translatably counter-sunk in the shaft" P) and this key actuates a suitable clutch (not shown) between the prime-mover'P and the shaft P. The transmission elements previously described are then maintainedin motion by the power imparted to the intermediate shaft and the cutter and the work are both. revolved at the relative rate determined by the two change gears 2 and as".

To manuallyshift the stanchion, a handwheel V (provided with graduations or micrometer adjustments) is aihired to a shaft that carries an angle gear V which. meshes with an angle gearV which is splined to the screw S and enables it to be turned by hand. The above described manual means enables the user very readily to bring the stanchion to any desired position with respect to the work-spindle for cutting spur gears.

To feed the cutter head, the parts will be in the positions and relations shown; the clutch F being engaged with the result that the shaft F is connected to the shaft Q and runs at the rate determined by the feed changegears designated generally by 7. The feeding motion is conveyed by a transmission consisting of an angle gear 1 mounted on the shaft Z and meshing with an angle gear 2 affixed to the shaft 8. A worm 4 011 that shaft drives a worm-wheel 5 which turns the shaft 6 and, through appropriate change-gears designated generally by 7 the gear 1' is driven and this gear is affixed to a sleeve 1" which is loosely mounted on the shaft Q but may be connected thereto by the clutch-teeth 1" by bodily shifting the sleeve 1' to connect the parts described. Angle gears F and F transmit the motion to the shaft F which is journaled in the stanchion and, at its upper end, has a gear F which meshes with a gear F which is a unit with a nut that turns about the non- That feed-screw is ailixed to the head H and is caused to move up or down, as the case may be, by the rotating nut and, in this manner, the cutter journaled on the head H is caused to feed downwardly whenever the parts are connected up as described. To avoid needless reference to certain features covered by the parent application, they have been omitted from the drawings. For instance, the power traverse extending from gear Q to gears Q and Q g also the means for manipulating the clutches 1", Q and F all of such means having been fully set forth in the parent case but forming no SDECiEll part of this divisional subject-inatter..

lVithout further analysis, the foregoing will so fully reveal the gist of this invention that otherscan, by applying current knowledge,'-readily adapt it for various utilizations byfretaining one or more of the features that, fromthestandpoint of the prior art, fairly constitute essential char acteristics of either the generic or specific aspects of this invention, and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims.

Having thus revealed this invention, I claim as new and desire to secure the following combinations and eleinents,.or equivalenls thereof, by Letters Patent of the United States:

1. A balanced-drive hobbing-machine comprising a bed; a relatively heavy stanchion shiftably supported thereon; a work-sup.- porting spindle non-shiftably journaled in said bed near one end thereof; a splined shaft and a parallel transmission shaft, each j0ur nailed on said bed transversely to said spindle; a pair of spur change gears connecting said two shafts; a splined transmission shaft journaleo on said stanchion parallel with said spindle; a head slidable on said stanchion; a hob-supporting spindle on said head; a pair of angle gears connecting said hob spindle with said splined transmission shaft, one of said angle gears being splined to'said shaft; a pair of angle-gears connecting said shaft to said first-mentioned shaft, one of said gears being splined to said tirstanentioner shaft; and a pair of angle gears connecting said parallel transmission shaft with said non-shiftable work spindle.

2. A balanced-drive bobbing-machine combining a bet; a work-supporting spindle occupying a fixed position on said bed; a heavy stanchion sh'iftably mounted on said bed; a hobsupporting spindle slidably carried by said stanchion; a transmission connecting said spindles and consisting of but three tlfillSlDlSSlOl'l shafts, the one being a work-iriving shaft, the other a hob-driving shaft and the third being an intermediate shaft, said intermediate shaft being splined and arranged parallel to the work-driving transmisson shaft and transversely to the hob-drving transmission shaft; the adjacent ends of said two parallel shafts being directly connected by two change gears of the spnr-tooth type, the hob-driving shaft being splined; an angie gear slidable 011 said intermediate shaft; said hob-driving shaft beinggeared at one end directly to said spindle and at its other end directly to said slidable angle-gear; a prime-mover geared directly to the intermediate shaft whereby the power for driving said spindles will be derived from the respective ends thereof; and means for etfecting a progressive relative translation between said spindles in a direction paral'lel'with the worlosupporting spindle.

3. A bobbing-machine combining a hobsupporting spindle and a work-supporting spindlearranged transversely thereto, a first splined transmission shaftarranged transversely to said hob-supporting spindle; a: worm-splined thereon; a second non-splined ransinission shaft arranged transversely to said worksupporting spindle; a worm affixed thereon; the worms on said shafts being in mesh with worm-wheels on the respective spindles; and a third splined transmis sion shaftarranged parallel with the second of said transmission shafts and having splined thereon one of a pair of bevel-gears directly connecting together both of the splined ransmission shafts; two intermeshing spur-gears, the one secured directly to said third shaft and the other directly to the second transmissionshaft parallel therewith; and means for effecting a progressive relative translation between said spindles in a direction parallel with the work-supporting spindle.

l. A bobbing-machine combining a'bed; a stanchion shiftable thereon; a hob-supporting spindle shiftable on said stanchion; a welk-supporting spindle non-shiftably journaled in said bed; a transmission connecting saidspindles and consisting in serial relation first of a pair of angled-gears, second of another pair of angled-gears, third of a pair of spur-gears, and fourth of a pair of angledgears; a solined transmission shaft directly connecting said first two pairs of angled gears; another splined transmission shaft diy connecting said second and third pairs gears; a third-non-splined shaft connecting the last two pairs of gears; a prime mover connected to an intermediate portion said transmission tr in, whereby the motion to the spindles will be transmitted in two paths, the one being through the second and first pairs of gears, and the other being through the third and fourth pairs of gears; and means for effecting a progressive feed of said hob-supporting spindle along said stanchion in a direction parallel with the work-supporting spindle.

A bobbing-machine combining a hobsupporting spindle and a work-supporting spindle; means for bodily shifting said hobsupporting spindle in a direction transverse to the axis of the other to adjust the offset relation between said spindles; a transmission connecting said. spindles and con sisting in serial relation first of a pair of angled-gears, second of av splined shaft third of a pair of angled-gears, fourth o another splined shaft, fifth of a pair of spurgears, sixth of a transmission shaft, and seventh of a pair of angledgears, one of the gears of the first pair being slidably shiftable on said first mentioned splined shaft, and one of the gears of the next mentioned pair being splined on said second mentioned splined shaft, said shaft being arranged to extend in a direction transverse to the axis of the work-supporting spindle; and means for effecting a progressive feed of said hobfor driving each of said spindles will be transmitted by but four gears, one of the four gears used for propelling the laterally shiftable hob-supporting spindle having its axis extending in a direction transverse to the axis of said work-supporting spindle and being splined to the shaft on which it is mounted; and means for effecting a translation of said hob-supporting spindle in directions parallel with and transverse to'the work-supporting spindle.

7. A hobbing-machine combining a hobsupporting spindle and a work-supporting spindle; a first splined shaft arranged transversely to one of said spindles; an angle gear slidably mounted on one end of said splined shaft and a spur-gear detachably secured directly to its other end; a second splined shaft arranged transversely to said first shaft; an angle gear on one'end of said second splined shaft and meshing directly with said first-mentioned angle-gear; a worm splined to said second splinedshaft; a worm-wheel meshing therewith for propelling one of said spindles, means including a detachable spur-gear meshing directly with said first-mentioned spur-gear for propelling the other spindle, and means for effecting a progressive relative translation between said spindles in a direction parallel with said work spindle.

8. A hobbing-machine combining a hobsupporting spindle, and a work-supporting spindle; a splined shaft arranged transversely to said spindles, an angle gear slidably mounted at one end of said splined shaft and a spur-gear detachably secured directly to its other end; two shafts arranged transversely to said spindles respectively, but one of said two shafts being splined, an angle gear secured to one end of the splined one of sald shafts and meshing directly with said first mentioned angle gear, a detachable. spur-gear secured directly to one end of the other of said two shafts and meshing directly with said first-mentioned spur-gear; a first worm splined to said splined shaft, and a second worm secured to the other of said two shafts; wormwheels meshing directly with said worms for propelling said spindles, and means for eflecting a progressive relative translation between said spindles in a. direction parallel with said work spindle.

9. A balanceddrive hobbing -machine comprising a bed; a relatively heavy stanchion shiftably supported thereon; a work supporting spindle non-shiftably journaled in said bed near one end thereof; an intermediate splined shaft and a parallel transmission shaft, each journaled on said bed transversely to said spindle; a pair of spur change gears connecting said two shafts; a splined transmission shaft ournaled on said stanchion parallel with said spindle; a head slidable on said stanchion; a hob-supporting spindle mounted at a fixed angle on said head; a single pair of skew angle gears connecting said hob spindle with said splined transmission shaft, one of said angle gears being splined to said shaft; a pair of anglegears connecting said shaft to said inter mediate shaft, one of said gears being splined to said intermediate shaft; and a pair of angle gears connecting said parallel transmission shaft with said non-shiftable work spindle.

10. A balanceddrive bobbing-machine combining a bed; a work-supporting spindle i occupying a fixed position on said bed; a

heavy stanchion shiftably mounted on said bed; a hob-supporting spindle slidably carried by said stanchion; a worm-wheel of the skew gear type on said spindle; a transmission connecting said spindles and consisting of but one intern'iediate and two transn'iission shafts, said intermediate shaft being splined and arranged parallel to the work-driving transmission shaft and transversely to the hob-driving transmission shaft; the adjacent ends of said two parallel shafts being directly connected by two change gears of the spur-tooth type, the hob-driving shaft being splined; a worm slidable thereon; angle-gear slidable on said intermediate shaft; said hob-driving shaft icing through said skew worm and wormwheel geared at one end directly to said spindle and being at its other end directly to said slidable angle-gear; a prin'ie-n'iover geared directly to the intermediate shaft whereby the power for driving said spindles will be derived from the respective ends thereof; and means for effecting a progressive relative translation between said pindles in a direction parallel with the work-supporting spindle.

11. A hobbing-machine combining a hobsupporting spindle-and a work-supporting spindle arranged transversely thereto, a first. splined shaft arranged transversely to said hob-supporting spindle; a worm-splined thereon; a second non-splined shaft arranged transversely to said work-supporting spindle; a worm affixed thereon; the worms on saic shafts being in mesh with worm- -wheels on the respective spindle, the worm IUU lL-i) arranged )arallel with the second of said transmission shafts and having splined thereon one of a pair of bevel-gears directly connecting together both of the splined transmiszion shafts; two intermeshing spurgcars, the one secured directly to said. third shaft and the other directly to the second transr sion shaft parallel. therewith; and means for effecting a progressive relative translation between said spindles in a direction parallel with the work-supporting spindle. 7 12. A hobbing-machin-e combining a bed; a stanchion shii'table thereon; a hob-suppi'irting spindle mounted at a fined angle thereon and shiftable on said stanchion; a work-supporting spindle non-shiftably journaled in said bed; tr fission connect ing said spindles and c sting in serial relation first of a pair of angl-edgears of the skew type, second of a pair of angledgcars, third of a pair of spur rs, and fourth of a pair of angled-g ars; two splineC transmission shafts directly connectin; in nrlt three pairs of gears in series; a third-non-splined shaftconnecting the last two pairs of gears; a prime-n'iover connected to said transmission tr in, whereby the motion to the spindles will be transmitted in two paths, the one being through the second and first pairs of gears, and the other being through the third and fourth pairs of gears; and means for effecting a progressive d of said hob-supporting spindle along said stanchion in a direction parallel. with the work-supporting spindle.

13. A hobbing-machine combining a hobsupport-ing spindle and a work-supporting spindle; means for bodily shifting said hobsupporting spindle in a direction transverse to the axis of the other to adjust the offset relation between said spindles; atransmis sion connecting said spindles and consisting in serial relation first of a pair of angledgears of the skew type, second of a pair of angled-gears, third of a pair of spur-gears, and fourth of a pair of angled-gears, two splined transmission shafts directly connecting the first and second and the second and third pairs of gears in series, one of the gears of the first pair being slidably shiftable on said first shaft, and one of the gears of the second pair being splined on said sec- 0nd shaft, said shaft being arranged to extend in a direction transverse to the axis of the work-supporting spindle; a third transmission shaft connecting said third and said fourth pairs of gears and means for effecting a progressive feed of said hob-supporting spindle in a direction parallel with the worksnpporting spindle. v

14. A hobbing-maeh ne comb ning a hobsupporting spindle and a work-supporting spindle; a first splined shaft arranged transversely to one of said spindles; an angle gear slidably mounted on one end of said; splined shaftand spur-gear detachably secured directly to its other end; a second splined shaft arranged transversely to said first shaft; an angle gear on one end of said secspindle; a splined shaft arranged transverser ly to said spindles, an an 'le gear slidably mounted at one end of said splined shaft and a spur-gear detachably secured directly to its other end; two shafts arranged transversely to said spindles respectively, but one of said two shafts being splined, an angle gear secured to one end of the splined one of said shafts and meshing directly with said first mentioned angle gear, a detachable spur-gearsecured directly to one end of the other of said two shaftsand meshing directly with said first-mentione l spurgear; :1 first worm splined to said splined shaft, and a second worm secured to the other of said two shafts; worm-wheels meshing directly with said worms for propelling said spindles, the worm-wheel for thehob-spindle'being of the skew type; and means for effecting a progressive relative translation between said spindles in a direction parallel with said work spindle.

In witness whereof I have hereunto subscribed my name.

WILLIAM F. ZllvlMERMANN. 

